Piano-action frame



(No Model.)

I. W. BOTHMER. PIANO ACTION FRAME.

ed June 11, 1895 INVENTOR W/TNESSES. I 6;.

A TTOHNEYS.

UNITED STATES PATENT OFFICE.

FREDERICK WILLIAM BOTHMER, OF LONG ISLAND CITY, NEYV YORK.

PIANO-ACTION FRAME.

SPECIFICATION forming part of Letters Patent No. 540,946, dated June 11, 1895.

Application filed November 17, 1894. Serial No. 529,120- (No model.)

To aZZ whom, it may concern:

Be it known that I, FREDERICK WILLIAM BOTHMER, of Long Island City, in the county of Queens and State of New York, have invented a new and Improved Piano-Action Frame, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved piano action frame, which is comparatively simple and durable in construction, and arranged to securely and firmly hold the actions in position and to prevent loosening of the arms carrying the pivots for the hammers, dampers and other parts of the action.

The invention. consists in certain parts and details, and combinations of the same, as will be hereinafter fully described and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the views.

Figure is a rear elevation in part of the improvement with some of the actions in position. Fig. 2 is a sectional side elevation of the same on the line 2 2 of Fig. 1, and Fig. 3 is a plan view of the support for the adjusting-rail.

The improved piano action frame is provided with a number of brackets A, placed equidistant apart and secured in the usual manner to the piano frame, the said brackets being made of metal. On the rear of the brackets A, are secured the rails B and O, by machine screws D passing through the rails and screwing in threaded apertures in the brackets A.

The rails B and C are connected with each other by short arms E, preferably arranged one alongside or next to a bracket A, as

plainly indicated in Fig. 1, the said arms E, engaging with their upper ends a longitudinal groove B formed in the under side of the rail B, the lower ends of the said arms being seated in a similar groove C formed in the top of the rail 0.

The top of the rail B is formed with a 1011- gitudinally-extendi'ng ridge B adapted to engage a correspondingly shaped groove formed in the under side of an arm F, secured to the rail by a machine screw G, passing through the arm and screwing into a threaded aperture in the rail B. The arm F extends transversely and forms the pivot at its inner end for the hammer H, and at its outer end the pivot for the damper I, of the particular ac tion for a single string, it being understood that the several actions are placed one alongside the other, as indicated in Fig. 1.

On the under side of the rail B are formed or secured the lugs B engaged by the pivot arms 1' of the damper bar 1 adapted to be actuated in the usual manner from the pedal, to throw the dampers 1 into or out of action whenever required.

011 the lower rail 0, and on the rear thereof, is formed a ridge C engaging a correspondingly shaped recess in the front faceof the arm J extending downwardly and carrying a lever L adapted to be actuated from the piano key N, as indicated in Fig. 2. The arm J is fastened in place on the rail 0 by a machine screw K, it being understood that this arm is in alignment with the corresponding arm F, for the particular hammer and key.

Into each of the connecting arms E screws. the threaded end 0 of a forwardly-extending arm 0, formed at its free end with a fork O engaged by a screw P, for fastening the adjusting rail P in position on each of the arms 0. The adjusting rail P carries the usual adjusting screw Q, for regulating the action in the usual manner.

It will be seen that as the rails B and C are made of metal and secured to the metal brackets, they form very firm supports for the pivot arms F and J, so that a displacement of the hammers H and dampers I, as well as the lever L and the other parts of the action, is not liable to take place. It will further be seen that the arms F and J are each securely fastened in place to their respective rail B or C by the use of the ridges B and O and the machine screws as previously mentioned. A strip of cloth, felt or similar material is preferably interposed between the arms F and the ridge B and a similar strip is interposed between the arms J and their ridge 0 so that the wooden arms and metallic rails are insulated one from the other. I

Having thus described my invention, I claim as new and desire to secure by Letters Patent ICO 1. A piano action 'frame, comprising metal brackets, an upper metallic rail secured to said brackets and constructed to carry the pivots of the hammer and damper, a lower metallic rail to carry the pivot of the hammer lever and likewise secured to the said brackets, and arms connecting the rails at intervals, substantially as described.

2. In a piano action frame, the combination of the metal brackets, the upper metallic rail secured thereto and having a longitudinal groove in its lower surface, said rail being. constructed to carry the pivots of the hammer and damper at its upper side, the lower metallic rail likewise secured on the said 15 brackets and provided with a longitudinal groove in its upper surface, said lower rail being constructed to carry the pivot of the hammer lever, and arms connecting the rails at intervals and engaging the longitudinal 2o grooves thereof, said arms being constructed to carry the regulating device of the action, substantially as shown and described.

FREDE RICK WILLIAM BOTHMER.

Witnesses:

JAMES FOWLER, THOMAS J. RUSSELL. 

